Fig. 1. (a)Structural diagram and energy level diagram of the perovskite solar cell based on the GO:Spiro-OMe-TAD composite HTL
[20]; (b)structural diagram of the perovskite solar cell based on the rGO:PCBM composite ETL
[22]; (c)SEM images of perovskite films on different substrates (ITO/GO, ITO/PEDOT:PSS, and bare ITO)
[29]; (d)PCE degradation trend for the perovskite solar cells with/without Ag-rGO after 330 days storage in 45%–55% relative humidity at room temperature
[38].
Fig. 2. (a)Schematic diagram of the perovskite solar cell based on the MoS
2:Spiro-OMe-TAD composite HTL
[47]; (b)energy level diagram of the perovskite solar cell based on the MoS
2:Spiro-OMe-TAD composite HTL
[47]; (c)impedance analysis spectrum of the perovskite solar cell based on the TiO
2:MoS
2 composite ETL (
Rs: the series resistance,
Rsc: the shunt resistance generated by electron selective contacts, and
Rrec; the shunt resistance associated with the active layer)
[52].
Fig. 3. (a)Energy level diagram of the perovskite solar cell based on the ZnO nanoparticles ETL
[64]; (b)schematic diagram of the photodetector based on the CsPbBr
3:ZnO heterostructure
[65]; (c)schematic diagram of the perovskite solar cell using α-CsPbI
3 quantum dots as the interface layer
[68]; (d)absorption spectra of different thin films (pristine PbS QDs, pristine CH
3NH
3PbI
3, and PbS QDs/CH
3NH
3PbI
3)
[69]; (e) SEM images of TiO
2 nanotubes before and after the perovskite deposition
[75]; (f)time-resolved photoluminescence decays of different thin films (CH
3NH
3PbI
3/NiO-NP, CH
3NH
3PbI
3/NiO-NS, and CH
3NH
3PbI
3/ZrO
2-NP)
[77].
Fig. 4. (a)Schematic diagram of the perovskite solar cell with CH
3NH
3PbI
3/Au-NRs@SiO
2 heterostructure
[83]; (b)schematic diagram and energy level diagram of the quasi-2 D perovskite solar cell incorporated with AuAg-NPs@SiO
2[86]; (c)schematic diagram of the perovskite solar cell with a configuration of FTO/Ag-NPs@compact-TiO
2/CH
3NH
3PbI
3:TiO
2/Au
[88]; (d)steady-state PL spectra of different films (CH
3NH
3PbI
3, TiO
2/CH
3NH
3PbI
3, and TiO
2:AuAg-NPs/CH
3NH
3PbI
3)
[92].
Fig. 5. (a) Energy level diagram of the perovskite solar cell incorporated with a PS layer and schematic diagram illustrating the carrier transfer at the interface between the perovskite and HTL layers
[95]; (b) schematic diagram of the perovskite solar cell with a the PVP layer inserted between the perovskite and the HTL
[96]; (c)SEM images of the perovskite films with/without PVP
[101]; (d) PCE degradation trend for perovskite solar cells devices with/without PVP after 30 days storage in 50% relative humidity at room temperature
[99].